Whenever any such land is sold by any state agency, county, or nonprofit land conservation organization, that portion of the net proceeds (sale price less actual expenses of sale) of such sale equal to the proportion that the grant by the State bears to the original cost of the land or other property shall be paid to the State. In the event any such land or other property is leased, rented, or otherwise disposed of, that portion of the rental or proceeds equal to the proportion that the grant by the State bears to the original cost of the land or other property shall be paid to the State. Any proceeds received by the State pursuant to this section that were originally paid out of the fund pursuant to section 173A-9 shall be redeposited in or credited to the fund. This section shall not apply to rents of property protected by permanent conservation easements established by grants from the fund.